Wheat is the second most important cereal in Kenya. However, production is severely constrained by both abiotic and biotic stresses.
We have ever said that a research found wheat has allelopathic potential,it is so eco-friendly.But to itselt,it can’t protect itself very well.
Severe infestations by russian wheat aphid (RWA) may result in yield losses of up to 90% while stem rust (Race “Ug99”) infected fields may suffer 100% crop loss. The two pests combined are seriously affecting wheat farmers’ incomes because of the heavy reliance on pesticides that increase the cost of production.
An article from American Journal of Plant Sciences studies three wheat varieties,and try to find a good wheat lines that is resistance to russian wheat aphid and stem rust:
“Kwale”, a Kenyan high yielding variety but susceptible to both RWA and “Ug99”; “Cook”, an Australian variety carrying stem rust resistance gene Sr36 conferring immunity to “Ug99”; and “KRWA9”, a Kenyan line with resistance to RWA but of poor agronomic attributes were used. A double cross F1 (DC F1) was obtained by crossing the F1 of “Kwale × Cook” and the F1 of “Kwale × KRWA9”. The DC F1 population was subjected to sequential screening for both RWA and “Ug99” resistance. Surviving DC F1 progenies were left to self pollinate to obtain the F2 of the double cross (DC F2). The DC F2 progenies were sequentially screened against RWA and “Ug99” to yield a population that was resistant to both RWA and “Ug99”. Genotyping of the DC F2:3 families were conducted to select homozygous resistant plants. Data indicated that the RWA and “Ug99” resistance genes were successfully pyramided. Though races with virulence for Sr36 have been reported, the gene provides immunity to race “Ug99” and can still be effectively used as a component for “Ug99” resistance breeding together with other Sr genes.
(source:SCIRP/ American Journal of Plant Sciences)